The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Typical stepped or continuously variable transmissions employ a hydraulic control system operable to perform various functions within the transmission. These functions include actuating torque transmitting devices such as drive/reverse clutches or torque converter clutches, setting belt pulley positions, transmission cooling, and lubricating the components of the transmission. The hydraulic control system typically includes a valve body that houses a plurality of valves and solenoids. The hydraulic control system is provided pressurized hydraulic fluid from a pump. A plurality of fluid passages formed within the valve body connect the pump to the valves and solenoids which selectively control the supply of pressurized hydraulic fluid to the various components of the transmission.
Solenoids are typically designated as normally high and normally low. A normally high solenoid allows hydraulic fluid to communicate through the solenoid when in a de-energized state. In contrast, a normally low solenoid does not allow hydraulic fluid to communicate through the solenoid when in a de-energized state. In certain configurations, it is desirable to have a normally high solenoid in order to assure the flow of pressurized hydraulic fluid to certain components, such as a drive clutch, during certain operating conditions, such as an electrical failure to the solenoid. However, normally high solenoids are typically more expensive and have larger packaging space than a normally low solenoid. Accordingly, there is a need in the art for a solenoid assembly that has the functionality of a normally high solenoid with the packaging space and costs of a normally low solenoid.